Natatory Ligament

- Anatomy:
- other name for the superficial transverse metacarpal ligament;
- these ligamentous fibers extend between the web spaces of the digits, and lie immediately beneath the skin, and helps create web space;
- digital nerves & vessels pass deep or dorsal to natatory ligaments;
- because the spiral band passes deep to the N/V bundle (just before it forms coalescence w/ the natatory ligament) the
aneurovascular bundle will be drawn to the midline if either the natory ligament or the spiral band become contracted;
- this ligament passes in radial-ulnar direction at each web space, w/ some fibers going distally to PIP on either side of each finger;
- the natatory liagment normal tightens as the finger abduct;
- in Dupuytren's contracture, there is thickening and contracture of the natatory ligament, which leads to loss of abduction;
- because the natatory liagment coalesces w/ the lateral cords, contracture of the natatory ligament may lead to PIP Joint contracture;
- deep transverse ligament:
- lies 3-4 mm deep to superficial transverse ligament;
- connects the MP volar plates together;
- digital vessels run between superficial and deep ligaments;
- lumbrical muscles passes palmar to deep transverse ligament;
- dorsal interossei pass dorsal to deep transverse ligaments;